Iran and the US have held "intensive talks" in recent weeks mediated by a regional country regarding a prisoner swap and the release of Iran's frozen assets abroad, according to Nour News late Saturday, Anadolu Agency reported.
The news agency affiliated with Iran's top security body said the release of prisoners will happen simultaneously.
It also said the release of Iran's frozen foreign exchange reserves will also take place "in the same framework," with Iran introducing new accounts for the purpose.
The issue of prisoners has been one of the key sticking points in Vienna nuclear talks, with Tehran repeatedly asking Washington to not tie the issue with the nuclear deal.
At least four American nationals with dual nationalities have been held in Iran for years on various charges, including espionage. Some Iranians are also jailed in the US, primarily for bypassing sanctions.
The announcement came minutes after US Secretary of State Antony Blinken in a Twitter post said his country "will never stop working until all US nationals held hostage or wrongfully detained around the world are home," while announcing the release of seven Americans detained in Venezuela.
Reports had been doing rounds about one of the four Iranian-Americans imprisoned in Iran, Bagher Namazi, being allowed to for medical treatment due to failing health.
Reports suggested that his son, Siamak Namazi, is also being freed.
The father-son pair were convicted on charges of "collaborating with a hostile government" in 2016 and 2015, respectively, and each sentenced to 10 years in prison.
Bagher's case was closed in 2020 but he was effectively barred from leaving the country.
He served as a provincial governor during the Pahlavi rule before 1979 and later became UNICEF's representative in several countries.
His son is a businessman and the longest-held American detainee in Iran.
Stephane Dujarric, a spokesperson for the head of the UN, confirmed the news in a statement Saturday, saying that the UN chief was "grateful" that Bagher had been "permitted to leave Iran for medical treatment abroad" and "pleased to learn" about his son's release from detention.
Last month, Bagher's family said the 85-year-old needed urgent surgery and urged the Iranian government to release his son to be with his father during the surgery.
The two other Iranian-Americans currently held in Iran include Emad Sharghi and Morad Tahbaz, who are also expected to be released under the prisoner swap deal.
In August, Iran's Foreign Ministry had called on Washington to release Iranian nationals held in US jails and to address the issue independent of the ongoing talks to salvage the nuclear deal.
The ministry expressed Iran's readiness to implement an existing agreement with the US on a prisoner swap, urging the Biden administration to not set "pre-conditions."
Meanwhile, as announced by Nour News, Iran's blocked assets overseas, mainly in South Korea, are also likely to be released as part of the agreement being worked out.
Tehran said more than $7 billion in foreign exchange reserves have been blocked by Seoul under US pressure, which has led to strains in ties over the years.
Negotiations to address the issue, including at the higher level, have failed to produce results.